1. Field of the Invention
The present invention relates generally to an apparatus for the treatment of foot conditions, and more particularly, to an orthosis constructed to unload weight off of an affected area of the foot thus aiding in the healing of foot conditions. In its most common usage, the present invention relates to an orthosis for the treatment of diabetic plantar ulcers, whereby body weight is borne by the orthosis to aid in the healing of this plantar skin condition.
2. Description of the Prior Art
Foot ulcers represent one of the most notable risk factors for lower extremity amputations in persons diagnosed with diabetes mellitus. Persons diagnosed with diabetes are typically classified as slow healers and are prone to debilitating foot ulcers due to both neurologic and vascular complications. Peripheral neuropathy can cause altered or complete loss of tactile sensation in the foot and/or leg, and in this regard, the diabetic patient with advanced neuropathy tends to loose the ability to discriminate between sharp-dull tactile sensation. Accordingly, any cuts or trauma to the foot of a diabetic patient with advanced neuropathy often go unnoticed for lengthy periods of time. At present, there is no known cure for neuropathy, although strict control over glucose levels has been shown to slow the progression of the neuropathy.
Further, a deformity commonly known as “charcot foot” occurs as a result of decreased sensation. Patients with “normal” tactile sensation in their feet automatically determine when too much pressure is being placed on an area of the foot. Once identified, the human body instinctively shifts position to relieve the stress. A patient with advanced neuropathy looses this important mechanism. As a result, tissue ischemia and necrosis may occur leading to plantar ulcers. Microfractures in the bones of the foot go unnoticed and untreated, resulting in disfigurement, chronic swelling and additional bony prominences.
Microvascular disease is an additional problem for diabetic patients, which can also lead to foot ulcers. It is well known that diabetes often results in a narrowing of smaller arteries, which narrowing cannot be resolved surgically. This microvascularization thus further prompts the diabetic patient to adhere to a strict glucose level regimen, maintain an ideal body weight and cease tobacco smoking in an attempt to reduce the onset of microvascular disease.
Should a diabetic patient develop a plantar ulcer, for whatever reason, treatment options are generally limited to a two-fold treatment plan. In the first instance, the prime objective is to obtain wound closure, which eliminates a portal of entry for bacterial invasion and development of limb-threatening infection. In the second instance, a further objective is to allow for a reduction in sited foot pressures or the “offloading” of tissues. In this regard, protective orthotic footwear has been shown to lower sited foot pressures and further has been shown to contribute to the healing and closing of wounds. Moreover, once a given plantar ulcer has been effectively closed, protective orthotic footwear has been shown to prevent the reoccurrence of plantar ulcers. Orthotic footwear has thus become an area of special interest to a number of industries reliant on the development of treatment devices for medical conditions. Accordingly, orthotic devices for the treatment of plantar ulcers and other foot abnormalities have been developed and are known in the prior art. Known orthotic devices for the treatment of plantar ulcers and other foot abnormalities, however, suffer from a number of deficiencies, several of which are described hereinafter.
U.S. Pat. No. 6,228,044('044 Patent), which issued to Jensen et al., discloses Methods and Apparatus for Treating Plantar Ulcers. This disclosure teaches a temporarily worn leg brace which comprises a pair of rigid shells, a fastening system for joining the shells together to form a unified brace and a combination of bladders which engage the patient's leg and tarsal region to off-weight the plantar surface, prevent plantar flexing and minimize shearing forces to the plantar surface. The volume of the bladders may be adjusted to maintain a uniform pressure between the bladders and the patient's leg. In addition to providing a means for off-weighting the plantar surface of a patient's foot, the brace is reusable and adjustable to accommodate changes in a patient's leg size. The '044 Patent does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '044 Patent does not disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 5,226,245('245 Patent); U.S. Pat. No. 5,762,622('622 Patent); U.S. Pat. No. 5,797,862('862 Patent); and U.S. Pat. No. 6,083,185('185 Patent), all of which issued to Lamont, disclose boot structures for use in the treatment of plantar conditions. In this regard, the '245 Patent discloses a Protective Boot Structure, which is designed for patients with arterial disease. The boot structure comprises a separate fluid-containing cushion which can be attached in a variety of positions on or in the boot to provide support for a patient's foot and leg primarily when bed-ridden, though a modest amount of ambulatory use is contemplated. The '622 Patent discloses a Medical Boot with Unitary Splint. This invention comprises a relatively soft boot component having a foot portion, a leg portion, and a relatively hard plastic splint formed with a foot portion and a leg portion. The foot portion of the splint is mounted inside the boot and the leg portion of the splint is outside the rear surface of the boot. The '862 Patent discloses a Medical Boot for Patient with Diabetic Foot. This invention is also designed for patients with arterial disease and comprises an insole formed with a heat-activated material to form a permanent impression of the bottom of the patient's foot. The insole is adapted for removable placement in a medical boot. The '185 Patent discloses a Medical Boot for Patient with Diabetic Foot. This disclosure details a liner for use with the invention disclosed in the '245 Patent and comprises a cushion placed inside a medical boot against an upper rear portion of the boot, to promote flotation support for the wearer's ankle when the cushion includes a soft midsection panel adapted to engage the ankle rear surface. A deformable fluid-containing pouch is removably disposed in a hollow interior space within the panel to provide ankle support. The pouch can be removed through a rear access opening that is normally closed a by a zipper means for closure.
These patents, which issued to Lamont, do not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the Lamont disclosures fail to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 5,197,942('942 Patent), which issued to Brady, discloses a Customized Foot Orthosis. This orthosis comprises a brace having at least a back portion and a sole portion, an aperture extending through the sole portion and means for fastening the orthosis securely to a patient's foot and lower leg. The aperture is positioned to correspond with the location of the ulcerated site on a patient's foot, thus relieving pressure from the ulcerated site when a patient's foot is weight-bearing, thereby permitting a patient to be mobile while simultaneously assisting in the aeration and healing of the ulcerated site. The '942 Patent, does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '942 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 5,833,639('639 Patent), which issued to Nunes et al., discloses a Short Leg Walker. This invention teaches and describes a short leg walker comprising a rigid sole and calf shell and an articulated rigid skin and dorsal shell. The shells are padded at selected locations with a non-inflatable padding such as foam or fiber padding and at other locations with an inflatable bladder and a second bladder between the inflatable bladder and the limb of the patient. The second bladder is responsive to deforming pressure exerted on it and will maintain its support of the limb when the pressure is removed. This construction is intended to be used to immobilize the foot, lower leg and ankle in lieu of a plaster of Paris cast, (See, Col. No. 1, Line Nos. 10-14) and no teaching is found for the treatment of plantar ulcers. The '639 Patent, thus, does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '639 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 5,370,604('604 Patent), which issued to Bernardoni, discloses a Kinesthetic Ankle-Foot Orthosis. This invention has been designed primarily to treat the condition commonly known as “drop foot” in which a patient is unable to lift the patient's foot. The orthosis described in the '604 Patent comprises a lower portion, which contacts the plantar surface of the foot. The lower portion is continuous with an upper portion, which contacts the posterior surface of the lower leg. The lower and upper portions are attached to a patient's leg by a strap extending around the proximal portion of a patient's lower leg. The lower portion of the orthosis further comprises apertures at selected locations to allow selected portions of the foot to contact the floor while the orthosis is being used. The '604 Patent does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '604 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 5,853,380('380 Patent), which issued to Miller, discloses a Soft Ankle/Foot Orthosis. This invention comprises an upper portion and a lower portion formed of layers of soft material to surround the foot and lower portions of the leg. The layers of soft material thus form a split shell, which is sized and shaped to receive the lower leg and foot of a person desirous of orthotic treatment. One or more reinforcing stays are fixedly sandwiched between the inner layer and the outer layer to assist in holding the shell in its molded shape. The rigid reinforcing stay may be sandwiched between the layers of soft material in a generally L-shape to provide additional support to the leg and foot. A plurality of releasable fasteners is used to hold the shell in place on the wearer. It is further noted that the '380 Patent does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '380 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 4,351,324('324 Patent), which issued to Bronkhorst, discloses a Therapeutic Walking Device. This device is designed to reduce the tendency of persons with cerebral palsy to walk on the balls of their feet. The device comprises a foot section and a calf section formed at a 90-degree angle. The foot section has a heel support and a toe support, which supports are spaced so as to prevent pressure from being exerted on the sole of the foot between the heel and toes. The leg section is strapped about the calf of the user's leg. The '324 Patent does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, to maintain the plantar surface in a healed unulcerated state. Further, the '324 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
U.S. Pat. No. 3,916,886('886 Patent), which issued to Rogers, discloses a Preformed Self-Conforming Drop Foot Brace. This brace comprises an upper calf portion and lower foot portion and is of such a structure that both the foot of the user and the lower portion of the brace maybe disposed in a shoe without alteration or modification of the latter. It is noted that due to the conforming nature of the brace, it is inconspicuous when worn for the upper portion of the brace may be situated within the confines of the trouser leg of a user, and the lower portion of the brace may be situated within a street shoe. The '886 Patent, however, does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, maintain the plantar surface in a healed unulcerated state.
U.S. Pat. No. 5,571,077('077 Patent), which issued to Klearman et al., discloses a Self-Supporting Foot Orthosis with Pivotally Mounted Cover. This invention comprises a generally L-shaped rigid shell for receiving a patient's lower leg and foot. The rigid shell further comprises a lower, correspondingly shaped rigid cover articulated at the rearmost portion of the upwardly extending part of the first shell. The cover may be pivoted downward, that is, away from the plantar portion of the first shell to provide a support that will elevate the patient's foot when the patient is lying down and which will cover the sole when it is pivoted toward the plantar portion of the foot. Apertures in the first shell allow the patient's foot to be treated and inspected when the cover is pivoted away from the plantar portion of the foot. The '077 Patent does not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, maintain the plantar surface in a healed unulcerated state. Further, the '077 Patent fails to disclose an orthosis, which may be easily donned and inserted inside a patient's modified street shoe.
It will thus be seen from a review of the foregoing prior art references that the prior art thus perceives a need for a permanent orthosis, which may electively be worn throughout one's life, which may be easily donned and inserted inside a patient's modified street shoe. In this regard, it has been repeatedly shown that the cited patent disclosures do not disclose the use of a permanent orthosis, which may be easily worn to heal and close a plantar ulcer, and additionally, maintain the plantar surface in a healed, unulcerated state. Further, the cited prior art fails to disclose an orthosis for the treatment of plantar ulcers comprised primarily of molded polypropylene or a similar polyester resin, which may be easily donned and inserted inside a patient's modified street shoe. What is needed is a treatment device to aid in supporting the lower leg and foot of patients who have been diagnosed with diabetic neuropathic, charcot joint and plantar ulcers with our without foot deformity. Current treatment modalities for plantar ulcers include reducing weight-bearing events through the use of crutches or total contact casts or wheelchairs. Additionally, surgical intervention is often employed. In this regard, it is noted that many ulcerated patients undergo surgery to remove the infected ulcer through partial foot amputation or to remove prominent bony areas that cause pressure problems. Typically, many of these patients will either develop plantar ulcers in a new area of the foot or the patient will refrain from walking so as to prevent any new ulcers. Often, after surgery, the patient's gait is affected due to missing bone structure in the foot region. None of the aforementioned remedies, however, offer a permanent solution to unloading or relieving pressure at the ulcer site.